<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script>
			/*var a=[1,2,3,4,5,6,7,8];
			var i=0;
			while(i<a.length){
				console.log(a[i]);
				i++;
				}  升序*/ 
				  /*var a=[1,2,3,4,5,6,7,8];
				  var i=a.length-1;
				while(i>=0){
					console.log(a[i]);
					i--;
					}  降序*/
					/*let局部变量*/
					/*var a=[1,2,3,4,5,6,7,8];
					for(let j=0;j<a.length;j++){
						console.log(a[j]); 
					}循环*/
					/*var a=[1,2,3,4,5,6,7,8];
					let j=0;
					do{
						console.log(a[j]);
						j++;
					}while(j<a.length)  先判断后执行*/
					var a=[1,2,3,4,5,6,7,8];
					/*for  in  循环 
					for(let j in a){
						console.log(a[j]);
						}
						*/
					   /*for  of  循环 
					   for(let j of a){
					   	console.log(j);
					   	}
						*/
		</script>
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	<body>
	</body>
</html>
